Eyes: Tissue Function

Eyes are the organs of vision. Detection of light and its conversion into electrochemical impulses in neurons is their basic function. In higher organisms such as human beings, the eye is a complicated optical system that collects light from the surroundings, processes its intensity in the diaphragm, focuses it via lenses to form image, converts the formed image into electrical impulses, and finally transmits these impulses to the brain via neurons, which connect the optic nerve to the visual cortex and other areas of the brain.

[Page 401]Additional functions of the eye involve retinal photosensitive ganglion cells, which send signals along the retinohypothalamic tract to the suprachiasmatic nuclei to affect circadian cycle adjustment.

Regarding image formation, rays of light enter through a small hole known as the ...